1. Field of the Invention
The present invention relates to a seat frame-mounting structure for a split bench type vehicle seat and the like.
2. Background Information
A bench type seat, on which three people can sit, is structured such that the seat cushion and the seat back are continuous from the driver's seat to the front passenger seat. In a split bench type seat, the seat cushion and the seat back of a bench type seat are divided into a driver's seat portion and a front passenger seat portion so that seat back reclining adjustment, seat cushion front-and-back position adjustment and the like can be effected independently for the driver's seat portion and the front passenger seat portion. (See Repair Handbook, Vol. 2/2 for Toyota's Crown series automobiles, issued Sep. 3, 1987 by Toyota Jidosha kabuskiki Kaisha).
As illustrated in FIG. 4 showing a conventional seat frame-mounting structure, each seat portion of a split bench type seat 80 includes: a seat frame 82, which is press-formed from an iron plate and the like; a urethane pad and spring members (both unillustrated), such as a S-shaped springs, the urethane pad and the spring members being mounted to the seat frame 82; and, a covering material 30, such as tricot or a woven fabric, which covers the surfaces of the former components. The seat frame 82 is fastened via brackets 22 to adjusting rails 20, which are disposed on an underbody, by means of bolts (not shown) and nuts 18. (Description and illustration of the seat back portions are omitted).
In order for the seat back reclining adjustment, the seat cushion front-and-back position adjustment and the like to be effected independently for the driver's seat portion and the front passenger seat portion, a total of four reclining lower arms 26 are necessary, one being provided respectively at left and right sides of each seat portion. The position of the reclining lower arm 26 is determined by the position of the seat back, and the reclining lower arms 26 must be positioned at the rear side of the seat frames 82. As a result, the portions of the seat frames 82, which correspond to the reclining lower arms 26 located at central sides in the transverse direction of the vehicle, protrude toward the rear. If the seat frames 82 are not protruded in this way, the rear side of the seat frames are divided at the reclining lower arm 26 portions, and strength of the seat frames 82 cannot be ensured. Therefore, it is difficult to provide a design in which strength is ensured without portions of the seat frames 82 protruding toward the rear.